1. Technical Field of the Invention
This invention most generally relates to spacing and support of planar components of optical communications systems, and more particularly to a method of providing uniform spacing and support between planar optical components of an opto/electronic device.
2. Background Art
Integrated circuit technology allows large numbers of VCSEL (Vertical Cavity Surface Emitting Laser) laser emitters/transmitters and p-i-n diode photo detectors/receivers to be integrated into large, two dimensional planar arrays, with one or more such arrays mounted on a common ASIC (Application Specific Integrated Circuit) substrate, as by flip-chip methods, also known as hybridization mounting techniques, each emitter and detector of the array making electrical connections with circuitry previously constructed in the ASIC substrate. This compound device, when coupled to a terminal end or node of an optical link such as the end of a fiber optic bundle, provides an electro/optical communications interface where the optical transmission path is configurable independent of the location and orientation of the emitter array or sub-array as compared to the respective detector array or sub-array, as with a multi-channel fiber optic bundle. This capability enables uni-directional or bi-directional optical communications between a local processor section on or electrically connected to the host ASIC substrate and other optical processors or similarly equipped electronic processors on the host ASIC device, or between the local processor section and other optical or electronic processors on other associated or remote ASIC substrates or devices.
As the density of the arrays of emitters and detectors increases, coupling a multi-channel fiber optic cable, image guide, or other optical connector or terminating device to the transceiver array becomes an increasingly arduous task. In addition to the two dimensional considerations of aligning the terminating device with the array, i.e., X, Y and xcex8 (rotational) alignment, so as to align the independent path optical channels with appropriate emitters and detectors, there is the two-edged coupling problem of establishing the minimum practical spacing between the optical units and the optical link terminator for most efficient light transfer, and making it parallel, i.e., Z, pitch and roll (tip and tilt), while protecting the emitters and detectors from contact or contamination.
The problems posed above might be addressed by a suitable large array, fiber optic connector, image guide, or similar optical link connector/terminator or multi-connector scheme, where the connector has a planar attribute to its coupling face for uniformly close coupling alignment with the optical transmitter or receiver array. Such connectors and other connector problems and capabilities or at least aspects of them may be novel and may be the subject of other pending patent applications, but are not the subject of the present invention and the claims thereto. It is the spacing and support issues inherent in any scheme for connecting a photo array connector to the planar face or faceplate of an optical channel connection that is addressed herein.
It is an object of the invention to provide a method, and the resulting product or apparatus, for making a precision standoff and spacing structure in an opto-electronic interface apparatus, that rises above the optical face of a planar array of photo emitters and/or detectors. The standoff structure provides for proper parallel alignment and minimal interplanar spacing the attachment of a multi-channel optical link terminator or connector component to the face of the photo array or focal plane array, while providing good physical protection for the optical devices in the array.
It is a further object to provide for a standoff support structure that is fabricated about the optical array at the time the array is flip-chip bonded to an IC (integrated circuit) substrate. It is a yet further object to combine the bonding process material and step into the fabrication of the standoff structure.
It is another object of the invention to provide a standoff ridge around the perimeter of a planar optical array, or an internally distributed grid or other vertical wall pattern of standoff structure that will extend or enhance the functionality of the standoff structure.
It is an additional object of the invention to provide for the isolation of each optical device within the apparatus, or of select groupings of optical devices, by means of a standoff wall pattern of non-conductive material that extends through the opto-electronic layer of the apparatus and up to standoff height.
Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, which shows and describes embodiments of the invention, and illustrates the best mode for carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention.